1. Field of the Invention
The present invention generally relates to semiconductor devices and manufacturing methods of the same, and more specifically, to a semiconductor device wherein a transparent member is provided above a light receiving part which light receiving part is provided on a main surface of a semiconductor element and a manufacturing method of the semiconductor device.
2. Description of the Related Art
A solid-state image sensing device formed by packaging and modularizing a solid-state image sensor with a transparent member such as glass, a wiring board, wiring connecting the solid-state image sensor and the wiring board, sealing resin, and others, is well-known. Here, the solid-state image sensing device is, for example, an image sensor such as a Charge Couple Device (CCD) or Complementary Metal Oxide Semiconductor (CMOS).
In such a solid-state image sensing device, a transparent member is provided above the solid-state image sensor so that light is incident outside onto a light receiving surface of the solid-state image sensor via the transparent member.
For example, Japanese Laid-Open Patent Application Publication No. 5-13738 discloses a structure shown in FIG. 1 of a solid-state image sensing device 1 where a solid-state image sensor 3 is mounted on a lead frame 2 and connected to an outside connection lead with a bonding wire 4; an on-chip lens 5 is provided on an upper surface of the solid-state image sensor 3; a transparent glass plate 7 is provided via a space 9; and the solid-state image sensor 3 and the transparent glass plate 7 are integrally sealed by transparent resin 8.
Japanese Laid-Open Patent Application Publication No. 5-41506 discloses a structure shown in FIG. 2 of a solid-state image sensing device 10 where a solid-state image sensor 11 is mounted on a lead frame 12; a glass plate 17 is provided on an upper surface of the solid-state image sensor 11 via a micro-lens 14 and a resin layer 15 whose refractive index is low; and the glass plate 17, the solid-state image sensor 11, the micro-lens 14, and the resin layer 15 are integrally sealed by transparent resin 16.
Japanese Laid-Open Patent Application Publication No. 2004-363380 discloses an optical semiconductor device 20, as shown in FIG. 3, having an optical semiconductor element 22 having a circuit part 21 including a light receiving element formed on the surface thereof; a terminal part 27 provided on a rear surface of the optical semiconductor element 11 and electrically connected to the circuit part 21 via rewiring 25; a coating layer 28 made of a transparent material such as a glass plate covering the surface of the optical semiconductor element 22 via transparent adhesive resin 23; and sealing resin 26 covering a side surface of the coating layer 28 and the optical semiconductor element 22.
However, in the structure shown in FIG. 1, the transparent resin 8 is provided above the transparent glass plate 7. Hence, while the outside light may not be absorbed by the transparent resin 8, incident light may be scattered or reflected due to minute concave and convex area provided on the surface of the transparent resin 8.
In order to improve flatness of the surface of the molded transparent resin 8, it is necessary to improve smoothness of a mold, namely make the surface roughness of the mold small, or grind the surface of the transparent resin 8 after the molding process. Such a process causes increase of the manufacturing cost.
In addition, in the structure shown in FIG. 2, since the resin 16 is transparent, even if the transparent resin 16 extends on the light receiving surface of the glass plate 17, reduction of the amount of the light incident on the glass plate 17 may not be caused.
However, in order for the transparent resin 16 to continue having the light transmission characteristic, filler such as glass fiber or carbon particles is not added to the transparent resin 16.
Therefore, the transparent resin 16 has a large coefficient of thermal expansion and therefore may be deformed in a sealing process or a heating process when mounted on the electronic apparatus. A deformation such as a curve may be generated in the solid-state image sensing apparatus 10 by deformation of the transparent resin 16 so that a large force may be applied to the glass plate 17, the micro-lens 14 and the solid-state image sensor 11. This may cause decrease in the ability of the solid-state image sensing apparatus 10.
On the other hand, in the structure shown in FIG. 3, side surfaces of the coating layer 28 and the optical semiconductor element 22 coated by the sealing resin 26 are tilted surfaces. Therefore, the necessary width of the semiconductor element 22 is large so that the number of semiconductor elements (chips) in a single semiconductor substrate may be small. Furthermore, a special design is required whereby a chip gap in the semiconductor substrate is spread so that manufacturing cost is increased. In addition, a technique of, for example, photolithography is necessary for forming the rewiring 25 so that large-scale equipment is required.
Furthermore, even if a bad chip is included with the good chips, the coating layer 28 and the rewiring 25 are provided and resin sealing is implemented in a lump. Hence, the yield is lowered so that it may be difficult to manufacture the optical semiconductor device 20 at low cost.
Meanwhile, Japanese Laid-Open Patent Application Publication No. 2004-363380 also discloses a structure where the circuit element 21 and the terminal part 27 are electrically connected by a piercing electrode and the side surface parts of the coating layer 28 and the optical semiconductor device 22 are covered with the sealing resin 26.
However, in this structure, it is necessary to make the chip gap in the semiconductor substrate spread for sealing the side surfaces with the resin. In addition, a process from forming the rewiring to the resin sealing is made by the lump process and therefore the above-mentioned problem cannot be solved.